Monitoring System for Monitoring the Surrounding Area, in Particular the Area Behind Motor Vehicles

ABSTRACT

The invention relates to a monitoring system for monitoring the surrounding area, in particular the area behind motor vehicles and trailer vehicles having a plurality of distance sensors, which are arranged in a main plane and in at least one additional plane, for detecting objects or obstacles in the respective monitoring region ( 10′, 12′, 14′ ) which create the risk of a collision and/or limit the passage height and/or the passage width, and having a device ( 30 ), which evaluates the distance sensor signals, for ascertaining the current distance (actual value) of the motor vehicle from the detected object or obstacle and for comparing the actual value with a predefinable, vehicle-specific setpoint distance value and for outputting a warning signal if a predefinable difference value between the actual value and the setpoint value is not reached. In order to cover the monitoring region both in respect of area and also in respect of height, additional distance sensors ( 12, 14 ) are arranged on the vehicle in at least one additional plane in such a way that objects ( 20, 22 ) and obstacles which cannot be identified by the distance sensors ( 10 ) in the main plane ( 2 ) can be detected over the entire width of the vehicle.

The invention relates to a monitoring system for monitoring the surrounding area, in particular the area behind motor vehicles according to the preamble to claim 1.

Monitoring the area behind motor vehicles is a highly topical subject. Reversing when the driver sits in the front is particularly associated with significant hazards, since the driver cannot see the whole of the hazardous area. There is therefore a risk of colliding with buildings, goods, persons or other objects. When reversing commercial vehicles or construction machinery, the vehicles can collide with obstacles at various points, since the driver of the vehicle cannot see the area behind the vehicle. For this reason, a range of methods for monitoring the area behind the vehicle have already been proposed. Rear area monitoring systems that have already been employed mostly use distance sensors that are installed at one location or in one plane at the rear of the vehicle, and that indicate the distance from an obstacle. Use is made here of the ultrasonic echo method, employing ultrasonic sensors which in themselves are known, but which nevertheless only have a limited detection range, so that it is not in general possible to detect all the objects behind a vehicle.

The storage of limit values in a vehicle, in particular for the width and height of the vehicle, is also known—cf. DE 199 28 679 A1. The position of the vehicle is detected; as the vehicle approaches relevant structures, the vehicle data is compared with the data saved about the relevant structure. If the vehicle cannot pass the structure because it is too high or too wide, a warning is issued to the driver.

DE 10 2004 015 749 A1 discloses equipment for determining the possibility of a vehicle passing. That document proposes equipment for determining the possibility of a vehicle passing obstacles, the purpose of which is to estimate whether the height of the vehicle and/or the width of the vehicle permits it to pass between obstacles.

DE 10 2007 053 989 A1 discloses an arrangement for warning about obstacles affording insufficient height to pass and/or insufficient width to pass. Overhead obstacles and/or lateral obstacles in front of the vehicle are scanned in order to capture passage-related data from the obstacles, whereby the surface of the road is also scanned at the same time. The ascertained passage-related data from the obstacles is compared with passage-related data from the vehicle. A warning signal is issued to the driver if the passage-related data from the vehicle is greater than or equal to the passage-related data from the obstacles. The warning signals may be of a visual, audible or haptic nature.

An object detection system from Groeneveld is also known under the name of Greensight. This object detection system from Groeneveld provides an active camera detection system that provides the driver with a complete image of the situation behind his vehicle. In addition to the camera detection system, the object detection system from Groeneveld employs a sensor system that uses ultrasound to scan the area behind the vehicle. The detection area of the Groeneveld object detection system is distributed over three zones. The closer the object, the more insistent visual and audible warning signals become. The object detection system from Groeneveld can be used with two additional ultrasonic units at the top corners of the vehicle in order to detect objects such as hanging signs, half-open roller doors and tree branches. Here, however, only the outer edges of the vehicle are monitored.

The known rear area monitoring systems offer good coverage of the surface of the monitoring region. The monitoring region is not well covered at height, however.

The object of the present invention is therefore to develop the monitoring system of the type mentioned at the outset in such a way that the monitoring area or the detection region is well covered, over the entire vehicle width of the monitoring system, not only at the surface but also at height, at relatively little additional expense.

The object is achieved by the features of claim 1.

Advantageous and expedient further developments are specified in the dependent claims.

The invention first proposes that, in addition to a main monitoring plane of the monitoring system, at least one additional monitoring plane is provided, as a result of which the monitoring region or the detection region of the monitoring system is significantly extended, so that objects, obstacles and so forth can be detected that are not detected by the sensors in the main monitoring plane alone.

The invention employs distance sensors on the vehicle, in particular in the rear area of the vehicle, which, in accordance with a further development of the invention, are inherently known ultrasonic sensors.

With the aid of the monitoring system according to the invention it is possible to determine possibilities of a vehicle passing obstacles, since before an obstacle is reached the passage width and/or the passage height at the obstacle is measured by the sensors and can be compared with passage-related vehicle data. It is also possible in this way to react to current changes in the profile of the road. It is possible to avoid the situation in which a driver initially drives in between narrow obstacles but must then reverse since he cannot in fact pass the obstacles.

The monitoring system according to the invention can be employed generally to monitor the area surrounding vehicles, such that sensors can also be attached to the front of the vehicle, so that, for instance, an estimation of the passage width and/or passage height can be carried out both for forward travel as well as when the vehicle is in reverse.

According to a further development of the invention, it is provided that the distance sensors can be activated depending on the speed of the vehicle. The greater the speed of the vehicle, the faster, or the earlier, the distance sensors are activated, so that a timely warning of a possible collision is always ensured, and an unnecessary activation of the monitoring system can be avoided.

In an advantageous further embodiment of the invention it is provided that the monitoring system is first activated during reverse travel of the vehicle above a predefinable speed. This means that, no irritating warnings are triggered when maneuvering in narrow areas.

Another advantageous further embodiment consists in the provision of automatic braking of the vehicle when a risk of collision is detected, whereby the braking is carried out depending on the speed of the vehicle. These measures achieve greater monitoring certainty behind the vehicle. It is, moreover, possible to set different halting distances for the monitoring planes, so that, for instance, a greater halting distance is set when reversing with a lowered loading ramp than for the roof area.

In order to be able also to detect objects that could collide with the upper area and with the lower area of the vehicle, tree branches or low barriers for instance, additional sensors are arranged in the upper and lower areas of the vehicle according to another further development of the invention.

The invention is explained in more detail below with the help of the attached drawing.

It shows

FIG. 1 a schematic view of the rear part of a goods truck with distance sensors arranged in three monitoring planes and

FIG. 2 a block diagram of a monitoring system according to the invention.

The drawing provides a schematic illustration of the rear part of a goods vehicle 1 with the position of three planes, a central, main monitoring plane 4, an additional upper monitoring plane 6, and an additional lower monitoring plane 8.

Distance sensors 10, 12, 14 are arranged in the three planes in order to detect objects or obstacles in the respective monitoring region 10′, 12′, 14′ that present a risk of collision, and/or that limit the passage height and/or the passage width. The drawing schematically shows just one distance sensor in each plane. It is, of course, the case that preferably a plurality of distance sensors are arranged in each plane.

With the distance sensors 10 in the main plane 2, normal objects such as pillars 16 and high barriers 18 can be detected, while low barriers 20 can be detected with the lower additional plane 8 and objects located at height, such as overhanging loading ramps 22 as are shown schematically, or branches, can be detected with the upper additional plane 6.

The ultrasonic sensors 10, 12, 14 are connected via cable connections 30 to an evaluation unit 32. The results of the evaluation are supplied via an interface 34 to a vehicle computer, or directly to vehicle electronics (not illustrated). 

1. A monitoring system for monitoring the surrounding area, in particular the area behind motor vehicles and trailer vehicles, having a plurality of distance sensors, which are arranged in a main plane and in at least one additional plane, for detecting objects or obstacles in the respective monitoring region (10′, 12′, 14′) that present a risk of collision and/or that limit the passage height and/or the passage width, and having a device (32) that evaluates the signals from the distance sensors in order to determine the current distance (actual value) of the vehicle from the detected object or obstacle, and to compare the actual value with a predefinable, vehicle-specific setpoint distance, and to output a warning signal if the value falls below a predefinable difference value between the actual and setpoint values, characterized in that additional distance sensors (12, 14) are arranged on the vehicle in at least one additional plane (4, 6) in such a way that objects (20 or 22) and obstacles that are not recognized by the distance sensors (10) in the main plane (2) can be detected across the whole width of the vehicle.
 2. The monitoring system as claimed in claim 1, characterized in that the distance sensors (10, 12, 14) are ultrasonic sensors.
 3. The monitoring system as claimed in claim 1 or 2, characterized in that the distance sensors can be activated depending on the speed of the vehicle.
 4. The monitoring system as claimed in one of claims 1-3, characterized in that the monitoring system can first be activated during reverse travel of the vehicle above a predefinable speed.
 5. The monitoring system as claimed in one of claims 1 to 3, characterized in that the distance sensors can be set separately for each plane.
 6. The monitoring system as claimed in one of the preceding claims, characterized in that automatic braking of the vehicle is provided when a risk of collision is detected.
 7. The monitoring system is claimed in claim 6, characterized in that the braking is carried out depending on the speed of the vehicle.
 8. The monitoring system as claimed in one of the preceding claims, characterized in that in the upper and/or lower area of the vehicle further additional sensors are arranged in order to scan and detect objects colliding with the upper and/or lower area of the vehicle, such as tree branches, overhanging loading ramps and low barriers.
 9. The monitoring system as claimed in claim 6, characterized in that different halting distances can be set for each monitoring plane.
 10. The monitoring system as claimed in claim 6, characterized in that the braking is carried out depending on the distance of the vehicle from the detected object. 